Some imaging apparatuses such as a digital camera and the like have a function of generating authentication data, which is used to authenticate if image data has not been altered, together with that image data.
However, in a conventional imaging apparatus with that function, it cannot be authenticated if image data generated by the self apparatus or the other apparatus has not been altered, unless a special apparatus is prepared.
The present invention has been made in consideration of the above problem, and has as its object to authenticate if image data generated by the self apparatus or the other apparatus has not been altered, without preparing for any special apparatus.